[gde061]

After a 1-month shakedown on my 2008 335xi, I've concluded that if I pull from 1st to 2nd in with anything resembling a quick clutch release, the car shudders. If I power shift and don't let out the clutch super slow, it shudders severely (I'm shuddering myself to think of the clutch burning up). Same going down 2nd to 3rd, constantly struggling to RPM match to avoid engine shudder. And off the line, I have to up the RMP's and/or really ride the clutch to get a smooth start. Above 2-3rd, etc. it shifts nice and smoothly.

So from my limited knowledge, my first thought was that the clutch disk coil springs are the issue... either worn out or they can't handle the power in the lower range -- I don't know the torque / hp the car is running at but it's got some Stage 2 bolt on mods: catless downpipes, bigger intercooler, dual cone intakes, chargepipe, etc. but I don't think it's quite FBO mod'd. No tune that I'm aware of. I saw a good video -- https://youtu.be/4Xth0jOJnwg where it looks like bearing failure in the dual mass flywheel might also be a common issue. I suppose it could be other issues too - damaged linkage, clutch oil leak, etc. - but it doesn't happen when I release the clutch super slow... even at high rpm.

OK, my head is spinning with the jargon and so many clutch upgrade options. And it's like 20 F here in Ohio and my garage has no heat, so the part of me that enjoys driving more than counting the money in my wallet wants to just go to a shop and say put in a stage 2 clutch, but I don't know for sure if that's going to make anything better, plus for all I know it already had a clutch upgrade at some point... I don't really even know enough about how it should pull to avoid getting sold down the river, as I have yet to find a shop near me that I would trust their work without looking over their shoulder.

Being new to the world of BMW and what their transmission / clutch "should" feel like, I'm looking for general as well as specific advice. I think the current set up is an 8-bolt (car is a 2008), so I could get a clutch kit I guess. Someone near me has a Luk 6-bolt clutch and flywheel for sale on Craigslist, but not sure if that would fit (like I know the clutch won't fit, but if I put the new flywheel on, then presumably the 6-bolt clutch would fit?) From what I can infer, Luk is like a stage 1 upgrade. So what would be a good stage 2 clutch, and what is a fair shop price for the work vs how much time would it take to do the job for a weekend warrior (looks like something that would be really hard without a lift / trans jack)? And should I be thinking about upgrading the flywheel to a single mass flywheel?

Thanks in advance for any advice!

[tisdrew]

I'd go ask for professional opinions/diagnoses from 2-3 shops before buying anything. It does sound like the car has something aftermarket already in it. It could just be an overly aggressive clutch but yeah, maybe something is broken. Perhaps you can find a local n5x/bmw group and get someone with some knowledge to see if it's normal for a "race-style" clutch or something.

The 335is/550i clutch is a good upgrade for stock-turbo power or even small single turbos.

[gde061]

OK, thanks for the advice. I'm fourth owner according to public title records -- the guy I got it from did some small stuff but all the major mod's happened prior to that... he acquired from used dealership with no records.

I see so many of E9x's from this generation on the road in my area -- especially now that I have one -- there has to be some club or something... I just haven't connected with any local enthusiasts yet.

[Jeff@TopGearSolutions]

Originally Posted by gde061

After a 1-month shakedown on my 2008 335xi, I've concluded that if I pull from 1st to 2nd in with anything resembling a quick clutch release, the car shudders. If I power shift and don't let out the clutch super slow, it shudders severely (I'm shuddering myself to think of the clutch burning up). Same going down 2nd to 3rd, constantly struggling to RPM match to avoid engine shudder. And off the line, I have to up the RMP's and/or really ride the clutch to get a smooth start. Above 2-3rd, etc. it shifts nice and smoothly.

So from my limited knowledge, my first thought was that the clutch disk coil springs are the issue... either worn out or they can't handle the power in the lower range -- I don't know the torque / hp the car is running at but it's got some Stage 2 bolt on mods: catless downpipes, bigger intercooler, dual cone intakes, chargepipe, etc. but I don't think it's quite FBO mod'd. No tune that I'm aware of. I saw a good video -- https://youtu.be/4Xth0jOJnwg where it looks like bearing failure in the dual mass flywheel might also be a common issue. I suppose it could be other issues too - damaged linkage, clutch oil leak, etc. - but it doesn't happen when I release the clutch super slow... even at high rpm.

OK, my head is spinning with the jargon and so many clutch upgrade options. And it's like 20 F here in Ohio and my garage has no heat, so the part of me that enjoys driving more than counting the money in my wallet wants to just go to a shop and say put in a stage 2 clutch, but I don't know for sure if that's going to make anything better, plus for all I know it already had a clutch upgrade at some point... I don't really even know enough about how it should pull to avoid getting sold down the river, as I have yet to find a shop near me that I would trust their work without looking over their shoulder.

Being new to the world of BMW and what their transmission / clutch "should" feel like, I'm looking for general as well as specific advice. I think the current set up is an 8-bolt (car is a 2008), so I could get a clutch kit I guess. Someone near me has a Luk 6-bolt clutch and flywheel for sale on Craigslist, but not sure if that would fit (like I know the clutch won't fit, but if I put the new flywheel on, then presumably the 6-bolt clutch would fit?) From what I can infer, Luk is like a stage 1 upgrade. So what would be a good stage 2 clutch, and what is a fair shop price for the work vs how much time would it take to do the job for a weekend warrior (looks like something that would be really hard without a lift / trans jack)? And should I be thinking about upgrading the flywheel to a single mass flywheel?

Thanks in advance for any advice!

For your power level and what you are looking for, Spec Stage 2+ Clutch Kit. You can either replace the DMFW with a new OE or switch to SMFW.

6 Bolt will not fit 8 bolt cars. The clutches are the same but the flywheel is different.

You don't necessarily need a SMFW unless you are going above 500HP. SMFW are less expensive then a DMFW and last longer. However, with a SMFW you will have rattle noise at idle unless you raise your idle to about 900 RPM (flash tune required). So if that bothers you then consider a new OE DMFW.

Let me know if you need anything else.